1. Field of the Invention
The present invention relates to a self-adaptive image processing device and a processing method capable of determining how much high frequency component of the image is reserved according to the motion degree of the image.
2. Description of Related Art
Watching TV has become one of the entertainments for modern people. Generally speaking, the type of a video composite signal received by the TV set varies depending upon the difference of the definition of the color space. For example, in the YUV color space, the video composite signal includes a luminance component (Y), and a color information component (U and V), and the video composite signal is expressed as: Y+U sin(ωt)+V cos(ωt). In the YCbCr color space, the video composite signal includes a luminance component (Y), and a chrominance component (Cb and Cr), and the video composite signal is expressed as: Y+Cb sin(ωt)+Cr cos(ωt). In the YIQ (I; in-phase, Q: quadrature) color space, the video composite signal includes a luminance component (Y), and a color component (I and Q), and the video composite signal is expressed as: Y+Q sin(ωt+33°)+I cos(ωt+33°). Generally speaking, Y video component is a luminance signal, and the U, V, Cb, Cr, I, Q and the like, which are not the luminance signal, are all called the chrominance signal.
When the TV set receives the video composite signal, it is required to separate the luminance component Y from the color information component U/V (or chrominance component Cb/Cr, color component I/Q) and demodulate the color information component U/V. However, the color information component U/V (or chrominance component Cb/Cr, color component I/Q) after demodulation includes a baseband component and a high frequency component.
For example, in the YUV color space, the baseband component and the high frequency component of the color information component U/V after demodulation are expressed as follows:((U sin(wt)+V cos(wt))*(2 sin(wt))=U−U cos(2wt)+V sin(2wt)  (1);((U sin(wt)+V cos(wt))*(2 cos(wt))=V+V cos(2wt)+U sin(2wt)  (2).
In Equation (1), U represents the baseband component of the U component, and (−U cos(2wt)+V sin(2wt)) represents the high frequency component of the U component. Similarly, in Equation (2), V represents the baseband component of the V component, and V cos(2wt)+U sin(2wt) represents the high frequency component of the V component.
Currently, the low pass filter is used to remove the high frequency component. If a narrow-band low pass filer, suitable for processing dynamic images, is used in the static image processing, the color transition problem occurs, and the color is not sharp enough, because most of the high frequency component of the color is filtered. On the other aspect, if a wide-band low pass filter, suitable for processing static images, is used in the dynamic image process, the cross color problem occurs.
Therefore, a self-adaptive device and method for dynamically adjusting the color bandwidth is required, thus, in the static image processing, the color transition issue is reduced and the color is kept sharp; in the dynamic image processing, the cross color issue is reduced.